Interference canceling for mobile devices

ABSTRACT

A user-device implemented method includes encoding a first digital signal to generate a first digital baseband signal and modulate the first digital baseband signal to generate one or more RF signals corresponding to one or more frequency bands. The one or more RF signals are transmitted via one or more antennas. Substantially simultaneously with the transmission of the one or more RF signals, a second one or more RF signals is received via the one or more antennas. The second one or more RF signals are demodulated to generate a second digital baseband signal. The first digital baseband signal is subtracted from the second digital baseband signal to generate a modified second digital baseband signal.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to wireless communication devices, andmore particularly, interference handling in such wireless communicationdevices.

DESCRIPTION OF RELATED ART

In operation, a wireless communication devices use a portion of aparticular radio frequency spectrum for wirelessly transmitting andreceiving information. Regulatory bodies control the particularfrequency spectra for mobile communication systems, and detaileddefinition typically made by standardization organizations. However, ingeneral, each spectrum is divided into different frequency bands, witheach band defined as a portion/range of the various frequenciesallocated for certain type of usage, either licensed to a specificnetwork operator or unlicensed for usage by anyone.

In modern wireless systems, frequency bands can be defined in order tooperate in one out of two principal modes: time division duplex (TDD) orfrequency division duplex (FDD). In a time division based system, eachmobile terminal (e.g., user device) and/or base station in thecommunication system uses one single radio frequency range for bothsignal transmissions and receptions. To avoid direct interferencebetween transmitted and received signals, each terminal is switched intime between transmission and reception functions. In a frequencydivision mode, two different frequency ranges are allocated fortransmission and reception respectively. Accordingly, mobile terminalsusing FDD can transmit and receive signals simultaneously. In thismanner the transmitted signal from the terminal antenna(s) will notinterfere with the signals to be received in the same physicalantenna(s) although the transmitter and receiver are operating at thesame time.

Examples of frequency band definitions include frequency bands definedby the 3^(rd) Generation Partnership Project (3GPP) for usage inwideband code division multiple access (WCDMA) and LTE systems. Thebands are defined in 3GPP TS 25.101 and 36.101.

A recent development in wireless communication systems includes theusage of multiple frequency bands for simultaneous transmission betweena base station and a terminal. Generally speaking, the concept isreferred to as multi-carrier operation or carrier aggregation. The term“carrier” in this description refers to a carrier or center frequency ofa particular frequency band. When utilizing carrier aggregation, thecommunication system can be configured to combine spectra from two ormore bands into one larger aggregated spectrum resource. This can bedone in many different configurations, e.g., by combining two or morebands for additional base station to terminal (e.g., downlink) bandwidthand/or by combine bands for terminal to base station (e.g., uplink)aggregation.

Unfortunately, a potential consequence of carrier aggregation may beintra-device interference, occurring between simultaneously transmittedand received signals.

SUMMARY

According to one aspect, a user device includes a communicationinterface; and one or more processors, wherein the communicationinterface is configured to: receive, from the one or more processors, atransmit digital signal for transmission as one or more radio frequency(RF) signals; encode the transmit digital signal to generate a transmitdigital baseband signal; modulate the transmit digital baseband signalto generate the one or more RF signals; transmit, by a transmitter, theone or more radio frequency signals via one or more antennas; receive,by a receiver, and substantially simultaneously with the transmission ofthe one or more RF signals, a second one or more RF signals via the oneor more antennas; demodulate the second one or more RF signals togenerate a receive digital baseband signal; subtract, by an interferencecanceling unit, potentially interfering effects of the one or more radiofrequency (RF) signals based on the transmit digital baseband signalfrom the receive digital baseband signal to generate a modified receivedigital baseband signal; decode the modified receive digital basebandsignal to generate a decoded receive digital signal; and forward thedecoded receive digital signal to the one or more processors.

Additionally, the at least one of the one or more radio frequency RFsignals and the second one or more frequency RF signals include RFsignals in more than one frequency band.

Additionally, the more than one frequency band include a first uplinkband and a second downlink band, wherein the first uplink band has atleast one harmonic in an interfering frequency range corresponding tothe second downlink band.

Additionally, the interference canceling unit is further configured to:receive the transmit digital baseband signal; and generate a potentiallyinterfering signal based on some or all of the transmit digital basebandsignal, wherein the potentially interfering effects are subtracted fromthe receive digital baseband signal based on the potentially interferingsignal.

Additionally, the interference canceling unit is configured to generatethe potentially interfering signal by identifying time delay and/orphase shifts occurring from the transmitter to the receiver.

Additionally, the receive digital baseband signal includes more than onesignal corresponding to more than one downlink frequency band, andwherein the interference canceling unit is further configured to:subtract the potentially interfering signal from fewer than all of themore than one receive digital baseband signals.

Additionally, the user device comprises a mobile communication devicehaving telephone or data network capabilities.

Additionally, the user device is configured to support carrieraggregation of more than one carrier frequency band for uplink and/ordownlink.

According to another aspect, a mobile communication device-implementedmethod, includes: encoding a first digital signal to generate a firstdigital baseband signal; modulating the first digital baseband signal togenerate one or more RF signals corresponding to one or more frequencybands; transmitting the one or more RF signals via one or more antennas;receiving, substantially simultaneously with the transmitting of the oneor more RF signals, a second one or more RF signals via the one or moreantennas; demodulating the second one or more RF signals to generate asecond digital baseband signal; and subtracting the first digitalbaseband signal from the second digital baseband signal to generate amodified second digital baseband signal.

Additionally, at least one of the one or more radio frequency RF signalsand the second one or more frequency RF signals include RF signals inmore than one frequency band.

Additionally, the more than one frequency band include a first uplinkband and a second downlink band, wherein the first uplink band includesat least one component that potential interferes with the seconddownlink band.

Additionally, the at least one component comprises at least one harmonicof a carrier frequency range of the first uplink band.

Additionally, the method further includes receiving the first digitalbaseband signal by an interference canceling unit; and generating apotentially interfering signal based on some or all of the first digitalbaseband signal, wherein subtracting the first digital baseband signalcomprises subtracting the potentially interfering signal from the seconddigital baseband signal.

Additionally, the method further includes generating the potentiallyinterfering signal by identifying time delay and/or phase shiftsoccurring between transmitting the first one or more RF signals andreceiving the second one or more RF signals.

Additionally, the second digital baseband signal includes two or moresecond digital baseband signals corresponding to two or more downlinkfrequency bands, and subtracting the potentially interfering signal fromfewer than all of the two or more second digital baseband signals.

According to yet another aspect, a non-transitory computer-readablemedium containing instructions executable by at least one processor, forcausing the at least one processor to: encode a first digital signal togenerate a first digital baseband signal; modulate the first digitalbaseband signal to generate one or more RF signals corresponding to oneor more frequency bands; transmit the one or more RF signals via one ormore antennas; receive, substantially simultaneously with thetransmission of the one or more RF signals, a second one or more RFsignals via the one or more antennas; demodulate the second one or moreRF signals to generate a second digital baseband signal; and subtractthe first digital baseband signal from the second digital basebandsignal to generate a modified second digital baseband signal.

Additionally, at least one of the one or more radio frequency RF signalsand the second one or more frequency RF signals include RF signals inmore than one frequency band.

Additionally, the more than one frequency band include a first uplinkband and a second downlink band, wherein the first uplink band includesat least one component that potential interferes with the seconddownlink band.

Additionally, the computer-readable medium includes one or moreinstructions executable by at least one processor, that cause the atleast one processor to: receive the first digital baseband signal; andgenerate a potentially interfering signal based on some or all of thefirst digital baseband signal, wherein the instructions that cause theat least one processor to subtract the first digital baseband signalfurther cause the at least one processor to subtract the potentiallyinterfering signal from the second digital baseband signal.

Additionally, the computer-readable medium further includes one or moreinstructions executable by at least one processor, that cause the atleast one processor to: generate the potentially interfering signal byidentifying time delay and/or phase shifts occurring betweentransmitting the first one or more RF signals and receiving the secondone or more RF signals.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate one or more embodiments describedherein and, together with the description, explain the embodiments. Inthe drawings:

FIG. 1 is a diagram illustrating an exemplary environment in whichembodiments described herein may be implemented;

FIG. 2 is a diagram illustrating exemplary components of the user deviceof FIG. 1;

FIG. 3 is a diagram illustrating exemplary components of a device ofFIG. 1;

FIG. 4 is a block diagram of an exemplary implementation of thecommunication interface of FIG. 3, consistent with the embodimentsdescribed herein; and

FIG. 5 is a flow diagram illustrating an exemplary process for reducinginterference effects when implementing carrier aggregation.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings.The same reference numbers in different drawings may identify the sameor similar elements. The same reference numbers in different drawingsidentify the same or similar elements. Also, the following detaileddescription does not limit the invention. Instead, the scope of theinvention is defined by the appended claims and equivalents.

As described herein, a user device, such as a mobile device, a portabledevice, or a handheld device, may perform transmitter-to-receiverinterference canceling to enable implementation of carrier aggregationusing otherwise impracticable combinations of carrier frequency bands.According to an exemplary embodiment, when transmitting, the user devicedetermines potentially any interfering signals based on the transmissionof a data signal (e.g., to a base station or other device). The userdevice then, based on this determination, generates an interferingsignal for use in canceling the transmitter-based interference effectsin a simultaneously received signal. Upon receipt of one or moresignals, substantially simultaneously with the transmission of the datasignal, the user device is configured to subtract the interferenceeffects by subtracting the generated interfering signal from thereceived signal.

FIG. 1 is a diagram illustrating an exemplary environment in whichembodiments described herein may be implemented. Environment 100includes a user device 105 and a network 110. Network 110 includeswireless nodes 115-1 through 115-X, in which X>1 (also referred tocollectively as wireless nodes 115 or individually as wireless node 115)and network device 120.

The number of devices and the configuration of devices and networks inenvironment 100 are exemplary. According to other embodiments,environment 100 may include additional devices, fewer devices, differentdevices, and/or differently arranged devices, than those illustrated inFIG. 1. Additionally, according to other embodiments, environment 100may include additional networks

According to other embodiments, a single device illustrated in FIG. 1Amay be implemented as multiple devices and/or multiple devices may beimplemented as a single device. A device may be implemented according toa centralized computing architecture, a distributed computingarchitecture, or a cloud computing architecture. Additionally, a devicemay be implemented according to one or multiple network architectures(e.g., a client device, a server device, a peer device, or a combinationthereof).

Also, one or more functions and/or processes described as beingperformed by a particular device may be performed by a different device,or some combination of devices, which may or may not include theparticular device.

Environment 100 may be implemented to include wired and/or wirelessconnections among the devices and the network illustrated. A connectionmay be direct or indirect and may involve intermediary device(s) and/ornetwork(s) not illustrated in FIG. 1. Additionally, the number and thearrangement of connections between the devices and the network areexemplary.

According to an exemplary embodiment, user device 105 comprises aportable device, a mobile device, a wrist-worn device, or a handheldcomputing device that operates as described herein. By way of example,user device 105 may be implemented as a smart phone, a wirelesstelephone (e.g., a cellphone, etc.), a personal digital assistant (PDA),a data organizer, a picture capturing device, a video capturing device,a Web-access device, a music playing device, a location-aware device, agaming device, a computing device, and/or some other type of usercommunication device (e.g., a vehicular-based device, etc.). Asdescribed below, according to an exemplary embodiment, user device 105comprises interference-handling components for reducing or eliminatingthe effects of carrier aggregation based interference resulting fromconnections with network 110.

Network 110 includes one or multiple networks. For example, network 110includes a wireless network (e.g., mobile network, cellular network,non-cellular network, an ad hoc network, etc.). By way of example,network 110 may be implemented as a Long Term Evolution (LTE) network,an evolved High Rate Packet Data (eHRPD) network, a Global System forMobile Communications (GSM) network, a Universal MobileTelecommunication System (UMTS) network, a Wideband Code DivisionMultiple Access (WCDMA) network, an Ultra Mobile Broadband (UMB)network, a High-Speed Packet Access (HSPA) network, a WorldwideInteroperability for Microwave Access (WiMAX) network, an Institute ofElectrical and Electronics Engineers (IEEE) 802.X network, a EvolutionData Optimized (EV-DO) network, a Code Division Multiple Access(CDMA)-based network, or some combination thereof.

Wireless node 115 comprises a device that wirelessly communicates withuser device 105. By way of example, wireless node 115 may be implementedas an evolved Node B (eNB), a base station (BS), a base stationcontroller (BSC), a Node B, a base transceiver station (BTS), a relaynode, a repeater, a home eNB (HeNB), a home node B (HNB), an edge node,a radio node, or a microwave node. Wireless node may support one accessand/or wireless technology or multiple access and/or wirelesstechnologies.

Furthermore, wireless node 115 may include one or more network devicesthat are configured to respond to access requests from user device 105,negotiate access to user device 105 on one or more frequency channels,and forward information from user device 105 to one or more additionalelements within network 110.

Consistent with embodiments described herein, wireless nodes 115 anduser device 105 may each be configured to support carrier aggregationcommunication in which two or more frequency bands are combined foruplink, downlink, or both between user device 105 and wireless nodes115.

As used herein, carrier aggregation refers to a component of theLTE-Advanced specification (i.e., in which a number of different carriersignals (also referred to as component carriers) are combined to providehigh uplink and downlink bandwidths. More specifically, each componentcarrier can have a bandwidth of 1.4, 3, 5, 10, 15 or 20 MHz and as manyas five component carriers can be aggregated together, resulting in anmaximum aggregated bandwidth of 100 MHz.

Carrier aggregation can be used for both frequency domain division (FDD)and time domain division (TDD) architectures. In FDD, the number ofaggregated carriers can be different for the downlink carriers and theuplink carriers, and each carrier may be of different bandwidths. InTDD, the number of component carriers for uplink and downlink and thebandwidth of each carrier must be the same. Carrier aggregation can beperformed intra-band contiguous, in which contiguous component carriersare aggregated together, or inter-band, in which a frequency gap isprovided between the aggregated carriers.

In addition to transmitting using the carrier aggregated frequencies, RFtransmissions also include harmonics of the transmitted signals atinteger multiples of the carrier frequency. For example, FDD uplink band17 transmits in the range of 704 to 716 MHz. Thus, a first harmonicoccurs at 2×(704-716), which results in a first harmonic range of 1408to 1432 MHz. Similarly, a second harmonic occurs at 3×(704-716), whichresults in a second harmonic range of 2112 to 2148 MHz.

As described in additional detail below, these harmonics of the carrierfrequency may interfere with aggregated carrier signals used fordownlink. For example, an aggregated carrier that includes FDD band 4signals in the range of 2110 to 2155 MHz may interfere with the secondharmonic of a band 17 uplink carrier, which is output in the range of2112 to 2148 MHz.

Typically, non-aggregated carriers are used in pair bands such thatuplink and downlink frequencies are in non-overlapping ornon-interfering ranges. For example, FDD band 17 has an uplink range of1920-1980 MHz and a downlink range of 2110-2170 MHz. For TDD, uplinkcarriers and downlink carriers share a common frequency range, howeverare time separated to avoid interference. However, with carrieraggregation increasing the usable combinations of different carriers,the possibility of conflicting or interfering frequencies increasessignificantly, particularly considering harmonics of transmissionfrequencies. Embodiments described herein may ameliorate the deleteriouseffects of such interference without restricting the bands capable ofbeing aggregated.

FIG. 2 is a diagram illustrating exemplary components of user device105. As illustrated in FIG. 2, user device 105 may comprise a housing205, a microphone 210, a speaker 215, keys 220, and a touch display 225.According to other embodiments, user device 105 may comprise fewercomponents, additional components, different components, and/or adifferent arrangement of components than those illustrated in FIG. 2 anddescribed herein.

Housing 205 comprises a structure to contain components of user device105. For example, housing 205 may be formed from plastic, metal, or someother type of material. Housing 205 structurally supports microphone210, speaker 215, keys 220, and touch display 225.

Microphone 210 comprises a microphone. For example, a user may speakinto microphone 210 during a telephone call, speak into microphone 210to execute a voice command, to execute a voice-to-text conversion, etc.Speaker 215 comprises a speaker. For example, a user may listen tomusic, to a calling party, etc., through speakers 215.

Keys 220 comprise keys, such as push-button keys or touch-sensitivekeys. Keys 220 may comprise a standard telephone keypad, a QWERTYkeypad, and/or some other type of keypad (e.g., a calculator keypad, anumerical keypad, etc.). Keys 220 may also comprise special purpose keysto provide a particular function (e.g., send a message, place a call,open an application, etc.) and/or allow a user to select and/or navigatethrough user interfaces or other content displayed by touch display 225.Touch display 225 comprises a display having touch capabilities and/ortouchless capabilities (e.g., air touch, air-gesture).

FIG. 3 is a diagram illustrating exemplary components of a device 300depicted in FIG. 1. For example, device 300 may correspond to userdevice 105 and/or wireless node 115. As illustrated, device 300comprises a bus 305, a processor 310, memory/storage 315 that comprisessoftware 320, a communication interface 325, an input 330, and an output335. According to other embodiments, device 300 may comprise fewercomponents, additional components, different components, and/or adifferent arrangement of components than those illustrated in FIG. 3 anddescribed herein.

Bus 305 comprises a path that permits communication among the componentsof device 300. For example, bus 305 may comprise a system bus, anaddress bus, a data bus, and/or a control bus. Bus 305 may also includebus drivers, bus arbiters, bus interfaces, and/or clocks.

Processor 310 comprises a processor, a microprocessor, a data processor,a co-processor, an application specific integrated circuit (ASIC), asystem-on-chips (SOC), an application specific instruction-set processor(ASIP), a controller, a programmable logic device (PLD), a chipset, afield programmable gate array (FPGA), and/or some other processing logicthat may interpret and/or execute instructions and/or data. Processor310 may control the overall operation, or a portion of operation(s)performed by device 300. For example, processor 310 may performoperations based on an operating system, various applications, and/orprograms (e.g., software 320). Processor 310 may access instructionsfrom memory/storage 315, from other components of device 300, and/orfrom a source external to device 300 (e.g., another device or anetwork).

Memory/storage 315 comprises a memory and/or other type of storagemedium. For example, memory/storage 315 may comprise one or multipletypes of memories, such as, a random access memory (RAM), a dynamicrandom access memory (DRAM), a cache, a static random access memory(SRAM), a read only memory (ROM), a programmable read only memory(PROM), a ferroelectric random access memory (FRAM), an erasableprogrammable read only memory (EPROM), s static random access memory(SRAM), a flash memory, and/or some other form of hardware for storing.Memory/storage 315 may comprise a hard disk (e.g., a magnetic disk, anoptical disk, a magneto-optic disk, a solid state disk, etc.) and acorresponding drive. Memory/storage 315 may be external to and/orremovable from device 300, such as, for example, a Universal Serial Bus(USB) memory, a dongle, etc. Memory/storage 315 may store data, software320, and/or instructions related to the operation of device 300.

Software 320 comprises software, such as, for example, an operatingsystem and, application(s) and/or program(s). Software may comprisefirmware. By way of example, in the case that device 300 corresponds touser device 105, software 320 may comprise a telephone application, avoice recognition application, a multi-media application, a textingapplication, an instant messaging application, etc. According to anexemplary embodiment, user device 105 includes software configured toprovide carrier aggregation interference handling, as described herein.

Communication interface 325 comprises a wireless communicationinterface. For example, communication interface 325 comprises one ormore antennas and a transmitter that converts baseband signals fromprocessor 310 to radio frequency (RF) signals for output via an antenna,and a receiver that may converts RF signals from the antenna to basebandsignals. Alternatively, communication interface 325 may include atransceiver that performs the functions of both a transmitter and areceiver. Communication interface 325 may operate according to one ormultiple protocols, communication standards, or the like. Communicationinterface 325 permits device 300 to communicate with other devices,networks, and/or systems, such as wireless nodes 115.

Input 330 permits an input into the device. For example, input 330 maycomprise a keypad (e.g., keys 220), a display (e.g., touch display 225),a touch pad, a button, a switch, a microphone (e.g., microphone 210), aninput port, a knob, and/or some other type of input component. Output335 permits the device to provide an output. For example, output 335 mayinclude a display (e.g., touch display 225), a speaker (e.g., speakers215), a light emitting diode (LED), an output port, a vibratorymechanism, or some other type of output component.

Device 300 may perform operations or processes in response to processor310 executing instructions (e.g., software 320) stored by memory/storage315. For example, the instructions may be read into memory/storage 315from another storage medium or from another device via communicationinterface 325. The instructions stored by memory/storage 315 may causeprocessor 310 to perform various operations or processes. Alternatively,the device may perform processes based on the execution of hardware.

FIG. 4 is a block diagram of an exemplary implementation ofcommunication interface 325 consistent with the embodiments describedherein. As shown in FIG. 4, communication interface 325 may include abaseband encoder 405, a transmit coupler 410, an RF transceiver 415having a transmitter 420 and a receiver 425, one or more antennas 430,an interference canceling unit 435, and a baseband decoder 440.

Baseband encoder 405 receives digital data from processor 310, such as adigital voice signal for transmission via RF transmitter 420. Forexample, baseband encoder 405 may be configured to encode a binarydigital signal using a predefined encoding scheme, such as convolutionalor turbo encoding to generate a signal for transmission via a physicallayer, such as a radio frequency signal.

Transmitter 420 is configured to convert the encoded baseband signalinto modulated RF signals based on one or more specified carrierfrequencies according to allocated transmitter band specifications. Forexample, as briefly described above, transmitter 420 may be configuredto generate RF signals using two or more aggregated bands. Transmitter420 may include a digital to analog converter (DAC) for converting theencoded digital baseband signal for RF transmission.

Antennas 430 may be configured to output and receive RF signals, e.g.,generated by transmitter 420 or for receipt by receiver 425.

Receiver 425 is configured to receive RF signals and demodulate theminto a corresponding baseband signal. As described above, the receivedRF signals may be received via more than one aggregated frequency band.Receiver 425 may include an analog to digital converter (ADC) forgenerating an encoded digital baseband signal corresponding to thereceived RF signal(s). For the purposes of this description, it isassumed that the received RF signals(s) are received substantiallysimultaneously with the transmission of the RF signals from transmitter420.

Consistent with implementations described herein, interference cancelingunit 435 may be configured to receive, as inputs, the encoded basebandsignals generated by baseband encoder 405 and the demodulated basebandsignals output by receiver 425. In addition, interference canceling unit435 may be configured to identify one or more potentially interferingcomponents, such as a frequency and related harmonic frequency of thetransmitted RF signal. Interference canceling unit 435 may then beconfigured construct a representation of the potentially interferingtransmit signal and subtract or remove any the effects of theconstructed representation from the received baseband signal prior todecoding by baseband decoder 440. Additional description of interferencecanceling unit 435 is set forth in detail below with respect to FIG. 5.

Baseband decoder 440 receives an encoded baseband signal frominterference canceling unit 435. In particular, baseband decoder 440receives a baseband signal in which interference caused by one or moretransmission frequencies has been removed or subtracted. Basebanddecoder 440 may be configured to decode the digital baseband signalusing the predefined decoding scheme to generate a decoded digitalsignal. Baseband decoder 440 then outputs the decoded digital signal toprocessor 310.

FIG. 5 is a flow diagram illustrating an exemplary process 500 forreducing interference effects when implementing carrier aggregation.Consistent with embodiments described herein, steps of process 500 areperformed by one or more components of user device 105, such as thecomponents of communication interface 325 described above with respectto FIG. 4.

Process 500 begins, in block 505, upon receipt of a digital data signalby baseband encoder 405. For example, baseband encoder 405 may receivedigital information from processor 310, such as information relating tovoice communications (e.g., telephone calls, VoIP media), or otherinformation, such as Internet-related information initiated or by anoperating system or application executed by processor 310.

Baseband encoder 405 encodes the digital data for transmission viatransmitter 420 to generate a transmit digital baseband signal (block510). For example, as described above, baseband encoder 405 may encodethe digital data using any of a number of encoding schemes, such asconvolutional encoding, etc. Baseband encoder 405 than passes theencoded baseband data signal to both transmitter 420 and interferencecanceling unit 435 (block 515). Upon receipt of the encoded transmitdigital baseband signal, transmitter 420 modulates the signal for outputvia a selected frequency band or a plurality of frequency bands, asinstructed by processor 310 (block 520), and outputs the signal(s) viaone or more of antennas 430 (block 530).

For example, as described above, implementations consistent withembodiments described herein support carrier aggregation technology inwhich uplink and or downlink transmissions may be performed using morethan one frequency band.

Receiver 425 may receive one or more RF signals via one or more ofantennas 430 (block 535). Consistent with the implementation of carrieraggregation, the received RF signals may be received in one or more thanone frequency bands substantially simultaneously with the output of theRF signal described above in relation to transmitter 420.

Once received, receiver 425 may demodulate the received signals andgenerate corresponding receive digital baseband signal(s) (block 540).The receive digital baseband signal(s) are then passed from receiver 425to interference canceling unit 435 (block 545).

Interference canceling unit 435, generates a digital version of thepotentially interfering signal based on the digital baseband signalreceived from baseband encoder 405 (block 550). For example,interference canceling unit 435, based on frequency band informationreceived from processor 310, may identify potentially interferingharmonic information of the one or more transmit frequency band(s) inview of the receive frequency bands. Using the example described above,interference canceling unit may determine that a third harmoniccomponent of the data transmitted via uplink band 17 (i.e., 2212-2148MHz) potentially interferes with data received via downlink band 4(i.e., 2110-2155 MHz). In other implementations, an entirety of thetransmit digital baseband signal is used as the basis for generating thepotentially interfering signal.

Furthermore, in some embodiments, interference canceling unit 435 mayalso identify any relevant time delay and phase shifts occurring fromtransmitter 420 to receiver 425 resulting in a modification of thetransmit signal(s). Based on this information, interference cancelingunit 435 may generate (or reproduce) a digital version of thepotentially interfering signal, which may include all or some of theinformation contained in the transmitted signal.

Interference canceling unit 435 then subtracts the generated potentiallyinterfering signal from the demodulated receive digital basebandsignal(s) from receiver 425 to generate a modified receive digitalbaseband signal(s) (block 555). For example, successive or parallelinterference cancelling (SIC/PIC) receivers may be implemented to removeor subtract the effects of the generated interference signal from thefirst signal from the digital baseband signal.

In some implementations, only the receive digital baseband signal(s)corresponding to the potentially interfering frequency bands may besubjected to the interference canceling. For example, assume that userdevice 105 is configured to operate using uplink band 17 and downlinkbands 4 and 17. As described above, in this scenario, the third harmoniccomponent of the data transmitted via uplink band 17 may interfere withdownlink band 4, however no component of uplink band 17 interferes withdownlink band 17. Accordingly, in some implementations, only the receivedigital baseband signal corresponding to downlink band 4 (i.e., thepotentially interfered with frequency band) are subjected tointerference canceling as described above.

In any event, the modified receive digital baseband signal is thendecoded by baseband decoder 440 for use by processor 310 (block 560).

Consistent with embodiments described herein, the above-describedtransmitter-based interference may be combined with other types of knowninterference canceling, such as multipath interference, interferencefrom other devices, etc. In some embodiments, the above-describedtransmitter-based interference canceling may be performed as an initialinterference canceling upon which additional interference processing maybe performed.

Systems and devices consistent with the aspects described herein mayexperience significantly reduced transmitter-to-receiver interference,thereby improving an effective received signal-to-interference ratio forthe desired signal. Such embodiments therefore enable carrieraggregation band combinations that may otherwise be very difficult oreven unrealistic to use.

The foregoing description of embodiments provides illustration, but isnot intended to be exhaustive or to limit implementations to the preciseform disclosed. Modifications and variations of the embodiments and/orimplementations are possible in light of the above teachings, or may beacquired from practice of the teachings. Additionally, or alternatively,one or more functions or processes described as being performed by userdevice 105 may be performed by other devices, such as wireless node 115.

An embodiment can also be implemented through computer readablecode/instructions stored by a storage medium. A storage medium maycomprise one or more of the storage media described above in relation tomemory/storage 315. The storage medium may also comprise other dataand/or information, such as a data file, a data structure, a programmodule, an application, etc. Computer readable code may comprise bothmachine code, such as produced by a compiler, and files comprisinghigher level code that may be executed by a computational device using,for example, an interpreter.

The flowchart and blocks illustrated and described with respect to FIG.5 illustrate an exemplary process according to an exemplary embodiment.However, according to other embodiments, the function(s) or act(s)described with respect to a block or blocks may be performed in an orderthat is different than the order illustrated and described. For example,two or more blocks may be performed concurrently, substantiallyconcurrently, or in reverse order, depending on, among other things,dependency of a block to another block.

The terms “comprise,” “comprises” or “comprising,” as well as synonymsthereof (e.g., include, etc.), when used in the specification is meantto specify the presence of stated features, integers, steps, orcomponents but does not preclude the presence or addition of one or moreother features, integers, steps, components, or groups thereof. In otherwords, these terms are to be interpreted as inclusion withoutlimitation.

The term “logic” or “component,” when used in the specification mayinclude hardware (e.g., processor 310), a combination of hardware andsoftware (software 320), a combination of hardware, software, andfirmware, or a combination of hardware and firmware.

The terms “a,” “an,” and “the” are intended to be interpreted to includeboth the singular and plural forms, unless the context clearly indicatesotherwise. Further, the phrase “based on” is intended to be interpretedto mean, for example, “based, at least in part, on,” unless explicitlystated otherwise. The term “and/or” is intended to be interpreted toinclude any and all combinations of one or more of the associated listitems.

In the specification and illustrated by the drawings, reference is madeto “an exemplary embodiment,” “an embodiment,” “embodiments,” etc.,which may include a particular feature, structure or characteristic inconnection with an embodiment(s). However, the use of these terms orphrases does not necessarily refer to all embodiments described, nordoes it necessarily refer to the same embodiment, nor are separate oralternative embodiments necessarily mutually exclusive of otherembodiment(s). The same applies to the term “implementation,”“implementations,” etc.

No element, act, or instruction disclosed in the specification should beconstrued as critical or essential to the embodiments described hereinunless explicitly described as such.

1. A user device comprising: a communication interface; and one or moreprocessors, wherein the communication interface is configured to:receive, from the one or more processors, a transmit digital signal fortransmission as one or more radio frequency (RF) signals; encode thetransmit digital signal to generate a transmit digital baseband signal;modulate the transmit digital baseband signal to generate the one ormore RF signals; transmit, by a transmitter, the one or more RF signalsvia one or more antennas; receive, by a receiver, and substantiallysimultaneously with the transmission of the one or more RF signals, asecond one or more RF signals via the one or more antennas, wherein thesecond one or more RF signals are in a carrier frequency band differentfrom a carrier frequency band that includes the one or more RF signals;demodulate the second one or more RF signals to generate a receivedigital baseband signal; subtract, by an interference canceling unit,following demodulation of the second one or more RF signals, potentiallyinterfering effects of the one or more RF signals based on the transmitdigital baseband signal from the receive digital baseband signal togenerate a modified receive digital baseband signal; decode the modifiedreceive digital baseband signal to generate a decoded receive digitalsignal; and forward the decoded receive digital signal to the one ormore processors.
 2. The user device of claim 1, wherein at least one ofthe one or more radio frequency RF signals and the second one or morefrequency RF signals include RF signals in more than one carrierfrequency band.
 3. The user device of claim 2, wherein the more than onecarrier frequency band include a first uplink band and a second downlinkband, wherein the first uplink band has at least one harmonic in aninterfering frequency range corresponding to the second downlink band.4. The user device of claim 1, wherein the interference canceling unitis further configured to: receive the transmit digital baseband signal;and generate a potentially interfering signal based on some or all ofthe transmit digital baseband signal, wherein the potentiallyinterfering effects are subtracted from the receive digital basebandsignal based on the potentially interfering signal.
 5. The user deviceof claim 4, wherein the interference canceling unit is configured togenerate the potentially interfering signal by identifying time delayand/or phase shifts occurring from the transmitter to the receiver. 6.The user device of claim 4, wherein the receive digital baseband signalincludes more than one signal corresponding to more than one downlinkfrequency band, and wherein the interference canceling unit is furtherconfigured to: subtract the potentially interfering signal from fewerthan all of the more than one receive digital baseband signals.
 7. Theuser device of claim 1, wherein the user device comprises a mobilecommunication device having telephone or data network capabilities. 8.The user device of claim 1, wherein the user device supports carrieraggregation of more than one carrier frequency band for uplink and/ordownlink.
 9. A mobile communication device-implemented method,comprising: encoding a first digital signal to generate a first digitalbaseband signal; modulating the first digital baseband signal togenerate one or more RF signals corresponding to one or more frequencybands; transmitting the one or more RF signals via one or more antennas;receiving, substantially simultaneously with the transmitting of the oneor more RF signals, a second one or more RF signals via the one or moreantennas, wherein the second one or more RF signals are in a carrierfrequency band different from a carrier frequency band that includes theone or more RF signals; demodulating the second one or more RF signalsto generate a second digital baseband signal; and subtractingpotentially interfering effects of the one or more RF signals based onthe first digital baseband signal from the second digital basebandsignal to generate a modified second digital baseband signal.
 10. Themethod of claim 9, wherein at least one of the one or more radiofrequency RF signals and the second one or more frequency RF signalseach include RF signals in more than one carrier frequency band.
 11. Themethod of claim 10, wherein the more than one carrier frequency bandinclude a first uplink band and a second downlink band, wherein thefirst uplink band includes at least one component that potentialinterferes with the second downlink band.
 12. The method of claim 11,wherein the at least one component comprises at least one harmonic of acarrier frequency range of the first uplink band.
 13. The method ofclaim 9, further comprising: receiving the first digital baseband signalby an interference canceling unit; and generating a potentiallyinterfering signal based on some or all of the first digital basebandsignal, wherein the subtracting further comprises subtracting thepotentially interfering signal from the second digital baseband signal.14. The method of claim 13, further comprising: generating thepotentially interfering signal by identifying time delay and/or phaseshifts occurring between transmitting the first one or more RF signalsand receiving the second one or more RF signals.
 15. The method of claim13, wherein the second digital baseband signal includes two or moresecond digital baseband signals corresponding to two or more downlinkfrequency bands, and subtracting the potentially interfering signal fromfewer than all of the two or more second digital baseband signals.
 16. Anon-transitory computer-readable medium containing instructionsexecutable by at least one processor, for causing the at least oneprocessor to: encode a first digital signal to generate a first digitalbaseband signal; modulate the first digital baseband signal to generateone or more RF signals corresponding to one or more frequency bands;transmit the one or more RF signals via one or more antennas; receive,substantially simultaneously with the transmission of the one or more RFsignals, a second one or more RF signals via the one or more antennas,wherein the second one or more RF signals are in a carrier frequencyband different from a carrier frequency band that includes the one ormore RF signals; demodulate the second one or more RF signals togenerate a second digital baseband signal; and subtract potentiallyinterfering effects of the one or more RF signals based on the firstdigital baseband signal from the second digital baseband signal togenerate a modified second digital baseband signal.
 17. Thecomputer-readable medium of claim 16, wherein at least one of the one ormore radio frequency RF signals and the second one or more frequency RFsignals include RF signals in more than one carrier frequency band. 18.The computer-readable medium of claim 17, wherein the more than onecarrier frequency band include a first uplink band and a second downlinkband, wherein the first uplink band includes at least one component thatpotential interferes with the second downlink band.
 19. Thecomputer-readable medium of claim 16, further comprising one or moreinstructions executable by at least one processor, that cause the atleast one processor to: receive the first digital baseband signal; andgenerate a potentially interfering signal based on some or all of thefirst digital baseband signal, wherein the instructions that cause theat least one processor to subtract the first digital baseband signalfurther cause the at least one processor to subtract the potentiallyinterfering signal from the second digital baseband signal.
 20. Thecomputer-readable medium of claim 19, further comprising one or moreinstructions executable by at least one processor, that cause the atleast one processor to: generate the potentially interfering signal byidentifying time delay and/or phase shifts occurring betweentransmitting the first one or more RF signals and receiving the secondone or more RF signals.